This circuit can generate signals of different frequencies, switched by a DC voltage. The frequencies are determined by the crystals. The circuit is from a 90s American documentation.
This configuration with the LM383 appears elsewhere on this site. The circuit shown was obtained...
This signal attenuator was suggested by Electronics Now magazine in April 1999. The circuit is...
The voltage gain of this DC amplifier is 100 times, given by the relationship between R2 and R1....